ESA Hubble: Elusive Giant Dark Matter Filament in MACS J0717 - 3D Video

This enormous image shows Hubble’s view of massive galaxy cluster MACS J0717.

The large field of view is a combination of 18 separate Hubble images.

The location of the dark matter is revealed in a map of the mass in the cluster and surrounding region, shown here in blue.

The filament visibly extends out and to the left of the cluster core.

CREDIT: NASA, ESA, Harald Ebeling (University of Hawaii at Manoa) & Jean-Paul Kneib (LAM)

Astronomers have taken their first 3D look at a gigantic filament of dark matter, an invisible cosmic structure that can only be detected by its gravitational effects it has on its surroundings.

The universe is thought to be structured like a tangled web, with long strings of mostly dark matter intersecting at giant galaxy clusters.

Since dark matter cannot be seen directly, these filaments are difficult to observe. But using the Hubble Space Telescope, astronomers have managed to probe one of the elusive cosmic strands in 3D.

The researchers sought out a 60 million light-year strand of dark matter around the massive galaxy cluster MACS J0717. The galaxy cluster is one of the largest yet seen and is about 5.4 billion light-years from Earth.

"From our earlier work on MACS J0717, we knew that this cluster is actively growing, and thus a prime target for a detailed study of the cosmic web," study researcher Harald Ebeling, of the University of Hawaii at Manoa, said in a statement Tuesday (Oct. 16).

 [Hubble's Dark Matter Strand View in 3D (Video)]